Macquarie Bank has sold Lime Taxis, its idiosyncratic fleet of Sydney cabs, but the investment bank has kept its hands on the company's fare transaction technology.

The bank launched the cab fleet in Sydney in 2006, heralded as a luxury taxi service for the city on account of the size and prestige of its vehicles, wheelchair accessibility and high-profile ownership.

The fleet also featured its own unique in-car transaction facility called Lime Live Payments -- developed in response to Cabcharge's market dominance of in-car payment systems.

Although the fleet has been sold, the payment technology will remain in the hands of Macquarie Group through its wholly-owned subsidiary MACT Holding Company, who developed the technology in conjunction with mobile wireless provider Digital Dispatch.

"Live transactions is and always has been a separate company owned by MACT Holding, Lime Taxis was simply the first application of the technology and there was never any intention to sell it off along with the Lime Taxi fleet," said a Macquarie Bank spokesperson.